'use client';

import { createContext, useContext, useEffect, useState } from 'react';

type Theme = 'dark' | 'light';

type ThemeProviderProps = {
    children: React.ReactNode;
    defaultTheme?: Theme;
    storageKey?: string;
};

type ThemeProviderState = {
    theme: Theme;
    setTheme: (theme: Theme) => void;
};

const initialState: ThemeProviderState = {
    theme: 'dark',
    setTheme: () => null,
};

const ThemeProviderContext = createContext<ThemeProviderState>(initialState);

export function ThemeProvider({ children, defaultTheme = 'dark', storageKey = 'theme', ...props }: ThemeProviderProps) {
    const [theme, setTheme] = useState<Theme>(() => {
        // Only access localStorage on client side
        if (typeof window !== 'undefined') {
            const storedTheme = localStorage?.getItem(storageKey) as Theme;
            return storedTheme || defaultTheme;
        }
        return defaultTheme;
    });

    useEffect(() => {
        // Sync theme with localStorage on client side
        const storedTheme = localStorage?.getItem(storageKey) as Theme;
        if (storedTheme && storedTheme !== theme) {
            setTheme(storedTheme);
        }
    }, [storageKey, theme]);

    useEffect(() => {
        const root = window.document.documentElement;
        root.classList.remove('light', 'dark');
        root.classList.add(theme);
    }, [theme]);

    const value = {
        theme,
        setTheme: (theme: Theme) => {
            localStorage?.setItem(storageKey, theme);
            setTheme(theme);
        },
    };

    return (
        <ThemeProviderContext.Provider {...props} value={value}>
            {children}
        </ThemeProviderContext.Provider>
    );
}

export const useTheme = () => {
    const context = useContext(ThemeProviderContext);

    if (context === undefined) throw new Error('useTheme must be used within a ThemeProvider');

    return context;
};
